Question: If $a + b = -1$ and $x + y + z = -10$, what is $-9y - 3b - 9x - 3a - 9z$ ?
Explanation: $= -3a - 3b - 9x - 9y - 9z$ $= (-3) \cdot (a + b) + (-9) \cdot (x + y + z)$ $= (-3) \cdot (-1) + (-9) \cdot (-10)$ $= 3 + 90$ $= 93$